diff --git a/.gitignore b/.gitignore
index 0ec9a24..bc0c0c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -130,6 +130,5 @@ Cargo.lock
 /npm
 
 # test files
-testfiles/*.csv
+testfiles/generated-*.csv
 !testfiles/generated-100.csv
-!testfiles/err-*-col*.csv
diff --git a/README.md b/README.md
index 649ee13..bef6358 100644
--- a/README.md
+++ b/README.md
@@ -26,14 +26,16 @@ The `DataFrame` class exposes two methods:
 
 - `colDtype`: retrieve the data type of the records contained within a column (integer, float, boolean or string)
 - `get`: get a column
-- `writeCsv`: write the dataframe to CSV (see the next paragraph)
+- `writeCsv`: write the dataframe to CSV (see dedicated paragraph)
+- `dropNull`/`fillNull`: Drop or fill null values (see dedicated paragraph)
+- `dropNan` / `fillNan`: Drop or fill NaN values (see dedicated paragraph)
 
 ```typescript
 const dt = df.colDtype('name')
 const colData = df.get('name')
 ```
 
-Based on the data type of the column, you can use one of the following helper functions to extract the associated array of data (as `string[]`, `boolean[]` or `number[]`):
+Based on the data type of the column, you can use one of the following helper functions to extract the associated array of data (as `(string | null)[]`, `(boolean | null)[]` or `(number | null)[]`):
 
 ```typescript
 import { DataType, asBooleanArray, asFloatArray, asIntArray, asStringArray } from '@cle-does-things/sunbears'
@@ -104,6 +106,26 @@ hello,1.2,4,true
 world,2.3,5,false
 ```
 
+### Null and NaN dropping and filling
+
+The DataFrame class supports also methods for filtering out or changing null values in the columns:
+
+```typescript
+const df = readCsv('test.csv')
+df.dropNull() // drop null
+df.fillNull() // fill null values with the zero value of their type
+```
+
+> NOTE: `fillNull` works with zero values, which means: `""` for string, `0` for integer and float, `false` for boolean
+
+You can filter out and change NaN values as well (only applies if there are float-typed columns):
+
+```typescript
+df.dropNan()
+df.fillNan() // fill with zero value
+df.fillNan(99.3) // fill with a specific value
+```
+
 ## Benchmarking
 
 `sunbears` was benchmarked using the `tinybench`-based script you can find [here](./benchmark/bench.ts). The script reports latency statistics related to the `readCsv` and `writeCsv` functions reading/writing increasingly large CSV files (100, 1000, 100.000 and 1.000.000 rows).
diff --git a/__test__/index.spec.ts b/__test__/index.spec.ts
index 3f62df5..b4a4967 100644
--- a/__test__/index.spec.ts
+++ b/__test__/index.spec.ts
@@ -189,3 +189,106 @@ test('Write to CSV works correctly', (t) => {
   }
   unlinkSync('testfiles/write-test.csv')
 })
+
+test('Dropping null values works correctly', (t) => {
+  const col1 = toStringColumn(['hello', 'world', null, 'bye', 'moon', 'hey'])
+  const col2 = toFloatColumn([1.2, 2.3, 0.3, null, 0.5, 8.9])
+  const col3 = toIntColumn([4, 5, 6, 7, null, 8])
+  const col4 = toBoolColumn([true, false, true, false, true, null])
+  const df = DataFrame.fromColumns({
+    col1: col1,
+    col2: col2,
+    col3: col3,
+    col4: col4,
+  })
+  t.is(df.len, 6)
+  df.dropNull()
+  t.is(df.len, 2)
+  t.deepEqual(asStringArray(df.get('col1')!)!, ['hello', 'world'])
+  t.deepEqual(asFloatArray(df.get('col2')!)!, [1.2, 2.3])
+  t.deepEqual(asIntArray(df.get('col3')!)!, [4, 5])
+  t.deepEqual(asBooleanArray(df.get('col4')!)!, [true, false])
+})
+
+test('Reading null values works correctly', (t) => {
+  const df = readCsv('testfiles/with-nulls.csv')
+  t.is(df.len, 5)
+  const col1 = asStringArray(df.get('col1')!)!
+  t.is(col1.filter((x) => x === null).length, 1)
+  t.deepEqual(col1, ['hello', null, 'bye', 'test', 'ciao'])
+  const col2 = asIntArray(df.get('col2')!)!
+  t.is(col2.filter((x) => x === null).length, 1)
+  t.deepEqual(col2, [1, 2, null, 3, 4])
+  const col3 = asFloatArray(df.get('col3')!)!
+  t.is(col3.filter((x) => x === null).length, 1)
+  t.deepEqual(col3, [0.1, 0.2, 0.3, null, 0.4])
+  const col4 = asBooleanArray(df.get('col4')!)!
+  t.is(col4.filter((x) => x === null).length, 1)
+  t.deepEqual(col4, [true, false, true, false, null])
+})
+
+test('Filling null values works correctly', (t) => {
+  const df = readCsv('testfiles/with-nulls.csv')
+  df.fillNull()
+  t.is(df.len, 5)
+  const col1 = asStringArray(df.get('col1')!)!
+  t.is(col1.filter((x) => x === null).length, 0)
+  t.deepEqual(col1, ['hello', '', 'bye', 'test', 'ciao'])
+  const col2 = asIntArray(df.get('col2')!)!
+  t.is(col2.filter((x) => x === null).length, 0)
+  t.deepEqual(col2, [1, 2, 0, 3, 4])
+  const col3 = asFloatArray(df.get('col3')!)!
+  t.is(col3.filter((x) => x === null).length, 0)
+  t.deepEqual(col3, [0.1, 0.2, 0.3, 0.0, 0.4])
+  const col4 = asBooleanArray(df.get('col4')!)!
+  t.is(col4.filter((x) => x === null).length, 0)
+  t.deepEqual(col4, [true, false, true, false, false])
+})
+
+test('Dropping NaN values works correctly', (t) => {
+  const col1 = toStringColumn(['hello', 'world', null, 'bye', 'moon', 'hey'])
+  const col2 = toFloatColumn([1.2, 2.3, 0.3, NaN, 0.5, 8.9])
+  const col3 = toIntColumn([4, 5, 6, 7, null, 8])
+  const col4 = toBoolColumn([true, false, true, false, true, null])
+  const df = DataFrame.fromColumns({
+    col1: col1,
+    col2: col2,
+    col3: col3,
+    col4: col4,
+  })
+  t.is(df.len, 6)
+  df.dropNan()
+  t.is(df.len, 5)
+  t.deepEqual(asStringArray(df.get('col1')!)!, ['hello', 'world', null, 'moon', 'hey'])
+  t.deepEqual(asFloatArray(df.get('col2')!)!, [1.2, 2.3, 0.3, 0.5, 8.9])
+  t.deepEqual(asIntArray(df.get('col3')!)!, [4, 5, 6, null, 8])
+  t.deepEqual(asBooleanArray(df.get('col4')!)!, [true, false, true, true, null])
+})
+
+test('Filling NaN values with a specific value works correctly', (t) => {
+  const col1 = toFloatColumn([1.0, 2.0, NaN, 3.0, 5.0, null])
+  const col2 = toFloatColumn([1.2, 2.3, 0.3, NaN, 0.5, 8.9])
+  const df = DataFrame.fromColumns({
+    col1: col1,
+    col2: col2,
+  })
+  t.is(df.len, 6)
+  df.fillNan(99.3)
+  t.is(df.len, 6)
+  t.deepEqual(asFloatArray(df.get('col1')!)!, [1.0, 2.0, 99.3, 3.0, 5.0, null])
+  t.deepEqual(asFloatArray(df.get('col2')!)!, [1.2, 2.3, 0.3, 99.3, 0.5, 8.9])
+})
+
+test('Filling NaN values with the zero value works correctly', (t) => {
+  const col1 = toFloatColumn([1.0, 2.0, NaN, 3.0, 5.0, null])
+  const col2 = toFloatColumn([1.2, 2.3, 0.3, NaN, 0.5, 8.9])
+  const df = DataFrame.fromColumns({
+    col1: col1,
+    col2: col2,
+  })
+  t.is(df.len, 6)
+  df.fillNan()
+  t.is(df.len, 6)
+  t.deepEqual(asFloatArray(df.get('col1')!)!, [1.0, 2.0, 0.0, 3.0, 5.0, null])
+  t.deepEqual(asFloatArray(df.get('col2')!)!, [1.2, 2.3, 0.3, 0.0, 0.5, 8.9])
+})
diff --git a/index.d.ts b/index.d.ts
index 25b9470..529dea2 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -7,22 +7,26 @@ export declare class DataFrame {
   colDtype(col: string): DataType | null
   get(col: string): ColumnData | null
   get columns(): Record<string, ColumnData>
+  dropNan(): void
+  fillNan(fillValue?: number | undefined | null): void
+  dropNull(): void
+  fillNull(): void
   writeCsv(path: string): void
 }
 
-export declare function asBooleanArray(column: ColumnData): Array<boolean> | null
+export declare function asBooleanArray(column: ColumnData): Array<boolean | undefined | null> | null
 
-export declare function asFloatArray(column: ColumnData): Array<number> | null
+export declare function asFloatArray(column: ColumnData): Array<number | undefined | null> | null
 
-export declare function asIntArray(column: ColumnData): Array<number> | null
+export declare function asIntArray(column: ColumnData): Array<number | undefined | null> | null
 
-export declare function asStringArray(column: ColumnData): Array<string> | null
+export declare function asStringArray(column: ColumnData): Array<string | undefined | null> | null
 
 export type ColumnData =
-  | { type: 'String'; field0: Array<string> }
-  | { type: 'Integer'; field0: Array<number> }
-  | { type: 'Float'; field0: Array<number> }
-  | { type: 'Boolean'; field0: Array<boolean> }
+  | { type: 'String'; field0: Array<string | undefined | null> }
+  | { type: 'Integer'; field0: Array<number | undefined | null> }
+  | { type: 'Float'; field0: Array<number | undefined | null> }
+  | { type: 'Boolean'; field0: Array<boolean | undefined | null> }
 
 export declare const enum DataType {
   String = 0,
@@ -33,10 +37,10 @@ export declare const enum DataType {
 
 export declare function readCsv(path: string): DataFrame
 
-export declare function toBoolColumn(data: Array<boolean>): ColumnData
+export declare function toBoolColumn(data: Array<boolean | undefined | null>): ColumnData
 
-export declare function toFloatColumn(data: Array<number>): ColumnData
+export declare function toFloatColumn(data: Array<number | undefined | null>): ColumnData
 
-export declare function toIntColumn(data: Array<number>): ColumnData
+export declare function toIntColumn(data: Array<number | undefined | null>): ColumnData
 
-export declare function toStringColumn(data: Array<string>): ColumnData
+export declare function toStringColumn(data: Array<string | undefined | null>): ColumnData
diff --git a/index.js b/index.js
index c53cb9c..42b8acf 100644
--- a/index.js
+++ b/index.js
@@ -77,8 +77,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-android-arm64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-android-arm64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -93,8 +93,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-android-arm-eabi')
         const bindingPackageVersion = require('@cle-does-things/sunbears-android-arm-eabi/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -114,8 +114,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-win32-x64-gnu')
         const bindingPackageVersion = require('@cle-does-things/sunbears-win32-x64-gnu/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -130,8 +130,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-win32-x64-msvc')
         const bindingPackageVersion = require('@cle-does-things/sunbears-win32-x64-msvc/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -147,8 +147,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-win32-ia32-msvc')
         const bindingPackageVersion = require('@cle-does-things/sunbears-win32-ia32-msvc/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -163,8 +163,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-win32-arm64-msvc')
         const bindingPackageVersion = require('@cle-does-things/sunbears-win32-arm64-msvc/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -182,8 +182,8 @@ function requireNative() {
     try {
       const binding = require('@cle-does-things/sunbears-darwin-universal')
       const bindingPackageVersion = require('@cle-does-things/sunbears-darwin-universal/package.json').version
-      if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-        throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+      if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+        throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
       }
       return binding
     } catch (e) {
@@ -198,8 +198,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-darwin-x64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-darwin-x64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -214,8 +214,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-darwin-arm64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-darwin-arm64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -234,8 +234,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-freebsd-x64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-freebsd-x64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -250,8 +250,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-freebsd-arm64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-freebsd-arm64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -271,8 +271,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-x64-musl')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-x64-musl/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -287,8 +287,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-x64-gnu')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-x64-gnu/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -305,8 +305,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-arm64-musl')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-arm64-musl/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -321,8 +321,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-arm64-gnu')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-arm64-gnu/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -339,8 +339,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-arm-musleabihf')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-arm-musleabihf/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -355,8 +355,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-arm-gnueabihf')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-arm-gnueabihf/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -373,8 +373,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-loong64-musl')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-loong64-musl/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -389,8 +389,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-loong64-gnu')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-loong64-gnu/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -407,8 +407,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-riscv64-musl')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-riscv64-musl/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -423,8 +423,8 @@ function requireNative() {
         try {
           const binding = require('@cle-does-things/sunbears-linux-riscv64-gnu')
           const bindingPackageVersion = require('@cle-does-things/sunbears-linux-riscv64-gnu/package.json').version
-          if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-            throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+          if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+            throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
           }
           return binding
         } catch (e) {
@@ -440,8 +440,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-linux-ppc64-gnu')
         const bindingPackageVersion = require('@cle-does-things/sunbears-linux-ppc64-gnu/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -456,8 +456,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-linux-s390x-gnu')
         const bindingPackageVersion = require('@cle-does-things/sunbears-linux-s390x-gnu/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -476,8 +476,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-openharmony-arm64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-openharmony-arm64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -492,8 +492,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-openharmony-x64')
         const bindingPackageVersion = require('@cle-does-things/sunbears-openharmony-x64/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
@@ -508,8 +508,8 @@ function requireNative() {
       try {
         const binding = require('@cle-does-things/sunbears-openharmony-arm')
         const bindingPackageVersion = require('@cle-does-things/sunbears-openharmony-arm/package.json').version
-        if (bindingPackageVersion !== '1.0.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
-          throw new Error(`Native binding package version mismatch, expected 1.0.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
+        if (bindingPackageVersion !== '1.1.0' && process.env.NAPI_RS_ENFORCE_VERSION_CHECK && process.env.NAPI_RS_ENFORCE_VERSION_CHECK !== '0') {
+          throw new Error(`Native binding package version mismatch, expected 1.1.0 but got ${bindingPackageVersion}. You can reinstall dependencies to fix this issue.`)
         }
         return binding
       } catch (e) {
diff --git a/src/lib.rs b/src/lib.rs
index 3e7c43c..66e8c8f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,11 @@
 #![deny(clippy::all)]
 
-use std::{collections::HashMap, fmt, fs::File, io::BufWriter};
+use std::{
+  collections::{HashMap, HashSet},
+  fmt,
+  fs::File,
+  io::BufWriter,
+};
 
 use anyhow::{anyhow, Result};
 
@@ -12,10 +17,10 @@ use napi_derive::napi;
 #[napi]
 #[derive(Clone)]
 pub enum ColumnData {
-  String(Vec<String>),
-  Integer(Vec<i64>),
-  Float(Vec<f64>),
-  Boolean(Vec<bool>),
+  String(Vec<Option<String>>),
+  Integer(Vec<Option<i64>>),
+  Float(Vec<Option<f64>>),
+  Boolean(Vec<Option<bool>>),
 }
 
 impl ColumnData {
@@ -53,7 +58,7 @@ impl fmt::Display for DataType {
 // ---------------------------------------- HELPER FUNCTIONS FOR DATA MODELS ----------------------------------------
 
 #[napi]
-pub fn as_float_array(column: ColumnData) -> Option<Vec<f64>> {
+pub fn as_float_array(column: ColumnData) -> Option<Vec<Option<f64>>> {
   match column {
     ColumnData::Float(f) => Some(f),
     _ => None,
@@ -61,7 +66,7 @@ pub fn as_float_array(column: ColumnData) -> Option<Vec<f64>> {
 }
 
 #[napi]
-pub fn as_int_array(column: ColumnData) -> Option<Vec<i64>> {
+pub fn as_int_array(column: ColumnData) -> Option<Vec<Option<i64>>> {
   match column {
     ColumnData::Integer(f) => Some(f),
     _ => None,
@@ -69,7 +74,7 @@ pub fn as_int_array(column: ColumnData) -> Option<Vec<i64>> {
 }
 
 #[napi]
-pub fn as_boolean_array(column: ColumnData) -> Option<Vec<bool>> {
+pub fn as_boolean_array(column: ColumnData) -> Option<Vec<Option<bool>>> {
   match column {
     ColumnData::Boolean(f) => Some(f),
     _ => None,
@@ -77,7 +82,7 @@ pub fn as_boolean_array(column: ColumnData) -> Option<Vec<bool>> {
 }
 
 #[napi]
-pub fn as_string_array(column: ColumnData) -> Option<Vec<String>> {
+pub fn as_string_array(column: ColumnData) -> Option<Vec<Option<String>>> {
   match column {
     ColumnData::String(f) => Some(f),
     _ => None,
@@ -85,22 +90,22 @@ pub fn as_string_array(column: ColumnData) -> Option<Vec<String>> {
 }
 
 #[napi]
-pub fn to_string_column(data: Vec<String>) -> ColumnData {
+pub fn to_string_column(data: Vec<Option<String>>) -> ColumnData {
   ColumnData::String(data)
 }
 
 #[napi]
-pub fn to_float_column(data: Vec<f64>) -> ColumnData {
+pub fn to_float_column(data: Vec<Option<f64>>) -> ColumnData {
   ColumnData::Float(data)
 }
 
 #[napi]
-pub fn to_int_column(data: Vec<i64>) -> ColumnData {
+pub fn to_int_column(data: Vec<Option<i64>>) -> ColumnData {
   ColumnData::Integer(data)
 }
 
 #[napi]
-pub fn to_bool_column(data: Vec<bool>) -> ColumnData {
+pub fn to_bool_column(data: Vec<Option<bool>>) -> ColumnData {
   ColumnData::Boolean(data)
 }
 
@@ -163,6 +168,216 @@ impl DataFrame {
     self.columns.clone()
   }
 
+  fn get_dtypes(&self) -> Vec<DataType> {
+    let mut dtypes = Vec::with_capacity(self.columns.len());
+    for k in self.columns().keys() {
+      let dt = self.col_dtype(k.clone()).unwrap();
+      dtypes.push(dt);
+    }
+    dtypes
+  }
+
+  #[napi]
+  pub fn drop_nan(&mut self) {
+    let dtypes = self.get_dtypes();
+    if dtypes.iter().all(|d| d != &DataType::Float) {
+      return;
+    }
+    let mut idxs = HashSet::new();
+    for i in 0..self.len as usize {
+      let mut has_nan = false;
+      for col in self.columns.values() {
+        match col {
+          ColumnData::Float(f) => {
+            if f[i].unwrap_or_default().is_nan() {
+              has_nan = true;
+            }
+          }
+          _ => continue,
+        }
+        if has_nan {
+          break;
+        }
+      }
+      if has_nan {
+        idxs.insert(i);
+      }
+    }
+    if !idxs.is_empty() {
+      for col in self.columns.values_mut() {
+        match col {
+          ColumnData::Boolean(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::Float(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::Integer(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::String(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+        }
+      }
+      self.len -= idxs.len() as u32;
+    }
+  }
+
+  #[napi]
+  pub fn fill_nan(&mut self, fill_value: Option<f64>) {
+    let dtypes = self.get_dtypes();
+    if dtypes.iter().all(|d| d != &DataType::Float) {
+      return;
+    }
+    let val = fill_value.unwrap_or_default();
+    for col in self.columns.values_mut() {
+      match col {
+        ColumnData::Float(f) => {
+          for item in f.iter_mut().take(self.len as usize) {
+            if item.unwrap_or_default().is_nan() {
+              *item = Some(val);
+            }
+          }
+        }
+        _ => continue,
+      }
+    }
+  }
+
+  #[napi]
+  pub fn drop_null(&mut self) {
+    let mut idxs = HashSet::new();
+    for i in 0..self.len as usize {
+      let mut has_none = false;
+      for col in self.columns.values() {
+        match col {
+          ColumnData::Boolean(b) => {
+            if b[i].is_none() {
+              has_none = true;
+            }
+          }
+          ColumnData::Float(b) => {
+            if b[i].is_none() {
+              has_none = true;
+            }
+          }
+          ColumnData::String(b) => {
+            if b[i].is_none() {
+              has_none = true;
+            }
+          }
+          ColumnData::Integer(b) => {
+            if b[i].is_none() {
+              has_none = true;
+            }
+          }
+        }
+        if has_none {
+          break;
+        }
+      }
+      if has_none {
+        idxs.insert(i);
+      }
+    }
+    if !idxs.is_empty() {
+      for col in self.columns.values_mut() {
+        match col {
+          ColumnData::Boolean(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::Float(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::Integer(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+          ColumnData::String(b) => {
+            let mut i = 0;
+            b.retain(|_| {
+              let keep = !idxs.contains(&i);
+              i += 1;
+              keep
+            });
+          }
+        }
+      }
+      self.len -= idxs.len() as u32;
+    }
+  }
+
+  #[napi]
+  pub fn fill_null(&mut self) {
+    for col in self.columns.values_mut() {
+      match col {
+        ColumnData::Boolean(b) => {
+          for item in b.iter_mut().take(self.len as usize) {
+            if item.is_none() {
+              *item = Some(false);
+            }
+          }
+        }
+        ColumnData::Float(f) => {
+          for item in f.iter_mut().take(self.len as usize) {
+            if item.is_none() {
+              *item = Some(0_f64);
+            }
+          }
+        }
+        ColumnData::String(s) => {
+          for item in s.iter_mut().take(self.len as usize) {
+            if item.is_none() {
+              *item = Some(String::new());
+            }
+          }
+        }
+        ColumnData::Integer(j) => {
+          for item in j.iter_mut().take(self.len as usize) {
+            if item.is_none() {
+              *item = Some(0_i64);
+            }
+          }
+        }
+      }
+    }
+  }
+
   #[napi]
   pub fn write_csv(&self, path: String) -> Result<()> {
     let file = File::create(&path)?;
@@ -178,7 +393,7 @@ impl DataFrame {
         let col = &self.columns[*key];
         match col {
           ColumnData::Boolean(b) => {
-            let v = if b[i] {
+            let v = if b[i].unwrap_or_default() {
               "true".to_string()
             } else {
               "false".to_string()
@@ -186,15 +401,15 @@ impl DataFrame {
             row.push(v);
           }
           ColumnData::Float(f) => {
-            let v = float_buf.format(f[i]).to_string();
+            let v = float_buf.format(f[i].unwrap_or_default()).to_string();
             row.push(v);
           }
           ColumnData::Integer(j) => {
-            let v = int_buf.format(j[i]).to_string();
+            let v = int_buf.format(j[i].unwrap_or_default()).to_string();
             row.push(v);
           }
           ColumnData::String(s) => {
-            row.push(s[i].clone());
+            row.push(s[i].clone().unwrap_or_default());
           }
         }
       }
@@ -265,10 +480,14 @@ pub fn read_csv(path: String) -> Result<DataFrame> {
     let vc = &col_to_vec[*c];
     let data: ColumnData = match d {
       DataType::Boolean => {
-        let mut v: Vec<bool> = vec![];
+        let mut v: Vec<Option<bool>> = Vec::with_capacity(vc.len());
         for el in vc {
+          if el.is_empty() {
+            v.push(None);
+            continue;
+          }
           match str_to_bool(el) {
-            Some(val) => v.push(val),
+            Some(val) => v.push(Some(val)),
             None => {
               return Err(anyhow!(
                 "Expecting bool at line {:?} for col {}",
@@ -281,10 +500,14 @@ pub fn read_csv(path: String) -> Result<DataFrame> {
         ColumnData::Boolean(v)
       }
       DataType::Float => {
-        let mut v: Vec<f64> = vec![];
+        let mut v: Vec<Option<f64>> = Vec::with_capacity(vc.len());
         for s in vc {
+          if s.is_empty() {
+            v.push(None);
+            continue;
+          }
           match s.parse::<f64>() {
-            Ok(val) => v.push(val),
+            Ok(val) => v.push(Some(val)),
             Err(_) => {
               return Err(anyhow!(
                 "Expecting float at line {:?} for col {}",
@@ -298,14 +521,25 @@ pub fn read_csv(path: String) -> Result<DataFrame> {
         ColumnData::Float(v)
       }
       DataType::String => {
-        let v = vc.iter().map(|s| s.to_string()).collect();
+        let mut v: Vec<Option<String>> = Vec::with_capacity(vc.len());
+        for s in vc {
+          if s.is_empty() {
+            v.push(None);
+            continue;
+          }
+          v.push(Some(s.to_string()));
+        }
         ColumnData::String(v)
       }
       DataType::Integer => {
-        let mut v: Vec<i64> = vec![];
+        let mut v: Vec<Option<i64>> = Vec::with_capacity(vc.len());
         for s in vc {
+          if s.is_empty() {
+            v.push(None);
+            continue;
+          }
           match s.parse::<i64>() {
-            Ok(val) => v.push(val),
+            Ok(val) => v.push(Some(val)),
             Err(_) => {
               return Err(anyhow!(
                 "Expecting integer at line {:?} for col {}",
diff --git a/testfiles/generated-100.csv b/testfiles/generated-100.csv
index ea61a40..bdeaab9 100644
--- a/testfiles/generated-100.csv
+++ b/testfiles/generated-100.csv
@@ -1,101 +1,101 @@
 name,age,is_working,height,phone_number,years_of_experience
-Anne,24,false,172.06195385839587,+1 1234,3.767044082274923
-Enid,36,true,164.17546867223956,+1 1234,3.9987730641281765
-Francis,45,true,167.66954681406762,0043-1234,0.4383413027655949
-Enid,34,true,161.30458950930952,+1 1234,1.0983771829465512
-Charles,25,false,151.67913999785412,0043-1234,2.434259647739991
-Dylan,31,true,161.16597974594205,0043-1234,3.276539501458718
-Charles,43,false,153.78110220498175,+1 1234,4.134995277849777
-Charles,25,true,166.40188604691568,0043-1234,3.4263596384326083
-Bob,23,false,158.38593329361092,0043-1234,1.0320864141187804
-Bob,22,false,174.30421224335603,0043-1234,0.30139282444920124
-Charles,25,false,167.36986172098074,+1 1234,3.6070863321158333
-Bob,47,true,155.77584934965734,+1 1234,0.3358753495974762
-Anne,47,true,152.07245609048525,0043-1234,3.978476753629136
-Anne,35,false,163.8284506948372,0043-1234,4.7375086847218375
-Anne,49,true,180.1237482982292,+1 1234,1.4734837130167757
-Francis,31,false,171.39476207206496,+1 1234,2.057482207163191
-Charles,20,false,150.85891722659494,+1 1234,1.8076413190188547
-Charles,26,true,157.73556835468887,0043-1234,3.2390834201030048
-Bob,28,false,180.22280208552263,0043-1234,0.11382435925677648
-Francis,50,true,162.39526970619806,+1 1234,0.8249470790353828
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diff --git a/testfiles/with-nulls.csv b/testfiles/with-nulls.csv
new file mode 100644
index 0000000..695cf2c
--- /dev/null
+++ b/testfiles/with-nulls.csv
@@ -0,0 +1,6 @@
+col1,col2,col3,col4
+hello,1,0.1,true
+,2,0.2,false
+bye,,0.3,true
+test,3,,false
+ciao,4,0.4,